Information retrieval (IR) is the activity of obtaining information resources relevant to an information need from a collection of information resources (e.g., web pages, images, text documents, multimedia content). Searches can be based on full-text or other content-based indexing. IR can be understood to comprise the science of searching for information in a document, searching for documents themselves, as well as searching for metadata that describe data, and for databases of texts, images or sounds. Automated IR systems such as web-based search engines are one of the most visible IR applications.
One paradigm in IR is personalization, which refers to search experiences that are tailored specifically to an individual's interests by incorporating information about the individual beyond the specific query provided. However, such personalized searches have been known to bias the results towards the interests of the searching user according to information available regarding the user and/or the user's preferences.